# HG changeset patch
# User Laman
# Date 2017-05-07 17:29:12
# Node ID e6752944fe6becf8bc37cccfc8df12728bf8fd17
# Parent  34f4027c1bd62db77975f61c1aec8bbe130a7544

hashtree loading and saving

diff --git a/src/hashtree.py b/src/hashtree.py
--- a/src/hashtree.py
+++ b/src/hashtree.py
@@ -1,6 +1,5 @@
 import hashlib
 import os
-import collections
 
 
 class HashTree:
@@ -9,7 +8,7 @@ class HashTree:
 	
 	## Prepares a tree containing leafCount leaves.
 	def __init__(self,leafCount):
-		self.store=[None]*(leafCount*2-1)
+		self.store=[b""]*(leafCount*2-1)
 		self.leafStart=leafCount-1
 		self.index=self.leafStart
 		self.leafCount=leafCount
@@ -27,7 +26,23 @@ class HashTree:
 		res.buildTree()
 		
 		return res
-		
+
+	@classmethod
+	def load(cls,filename):
+		with open(filename,"rb") as f:
+			stat=os.fstat(f.fileno())
+			size=stat.st_size
+			nodeCount=size//HashTree.HASH_LEN
+			res=cls((nodeCount+1)//2)
+
+			for i in range(nodeCount):
+				res.store[i]=f.read(HashTree.HASH_LEN)
+
+	def save(self,filename):
+		with open(filename,"wb") as f:
+			for h in self.store:
+				f.write(h)
+
 		
 	## Inserts a leaf at the first empty position.
 	#